This is assuming that the Clippers are actually proposing this as is. We don't know that, we just know that there have been talks.
I'm guessing they will fully explore how to get Garnett, then if that becomes impossible, may focus their efforts on Millsap. Or they may just stand pat and try to deal Bledsoe next year, since he does have another year on his contract.
Can the Clippers even feasibly sign Millsap and Paul? I don't think they would trade for Sap unless they thought they could realistically keep him past this year. Millsap is good, but I don't think he is good enough to warrant a half-year rental at the expense of a good asset that could yield a player who is under a longer contract (but lesser player) or draft picks. I'm assuming we would have to throw in some 1st round draft pick for the Clippers to consider.